Steering wander and Chinese parts?

Hi everyone! This is my first post to this site.
I have a 71 Demon which was purchased about 18 months ago. Despite having what looks to be new steering parts (ball joints, tie rod ends, idler arm, pitman arm) the steering has excessive wander. As I was removing the center link in preparation to adjust the backlash in the steering sector, I noticed the bolt for the idler arm was stripped!

I was afraid I would have to cut the bolt off, but to my surprise it came off WAY TOO EASY.
Correct me if I am wrong, but I'm pretty sure this bolt should be a 9/16-18 NF?

What I found was...and I can't find anybody on the inter-webs who have mentioned this, was a grade 10.9, 14mm (20mm head) with 18 tpi. YES, that's not a typo. The manufacturer of the part (I'm assuming Chinese) took a 14mm bolt and machined 18 tpi on it!

9/16= .562" 14mm = .551". There were no markings on the nut but if an SAE 9/16 nut was used, that could explain why the bolt threads were stripped and the bushing was not securely fastened. The bushing I.D. measured .572" and of course there is some built-in clearance in the K member mount holes. All this excessive clearance, plus the fact whoever installed this did not torque added up to what acted like a worn ball joint.

I suppose it is possible someone cobbled this together with a coffee can bolt but I don't think so. If you have aftermarket steering parts on your car, you may want to take a mirror and inspect the bolt head on your idler, especially if it was replaced and you are experiencing a wander issue. Here are a couple pictures to support my story. Hope this helps someone else.

All that said, if the bolt is torqued to correct value, it should be OK. In my case, the threads were stripped so it was not holding the bushing solidly and everything was moving around.
Jerry